Casing perforating gun



April 1, 1952 i J, o, Tow 2,591,319

CASING PERFORATING GUN Filed Sept. 23, 1946 INVENTOR JAMES 0. TOW

i8 l5 le BY' Y ATTORNEY l Patented Apr. 1*, 1952 CASING PERFORATING GUN .lames 0. Tow, Huntington Park, Calif., assigner to McCullough Tool Company, Los Angeles, Calif., a corporation of Nevada Application September 23, 1946, Serial No. 698,631

4 Claims.

My invention relates to guns employedfor perforating casing in wells and relates n particular to that type of gun wherein the powder charge is fired by an ignition effect produced in or at the outer end of the gun barrel or between the outer end of the projectile and the outer end of the gun barrel, this ignition eiect being produced by the explosion of an ignition charge of powder in a position ahead of the nose of the projectile So that the charge of powder in the chamber behind the projectile is fired either as the result of the driving of the projectile rearwardly to compress the firing charge vor by iiame or gases which pass rearwardly across the external face of the projectile into the firing charge.

It is an object of the invention to provide a perforating gun of simple construction having gun 'barrels removably supported in the gun body, these gun barrels being replaceable when wear or erosion makes this advisable.

It is a further object of the invention to provide a well perforating gun having a body with a laterally directed recess to receive a gun barrel which is of complex or composite form and comprises a number of parts arranged so that they may be separated when the gun barrel is removed from the recess, the separation of these parts opening or providing access to the powder chamber at the inner end of the gun bore.

lA further object of the invention is to provide a well perforating gun of the character set forth" in the preceding paragraph, wherein the cooperating parts of the gun barrel assembly are separable in a direction transverse to the axis of the gun bore, and a still further object of the invention is to provide a gun barrel having these characteristics wherein a main barrel member is provided with an axial bore to receive a projectile, `a powder receiving space at the rear end of the bore, and a lateral opening leading from the powder receiving space which is closed by a wall member which is held in place by the side wall of the barrel-receiving recess when the barrel assembly is placed therein.

A further object of the invention is to provide a perforating gun having a body with a laterally directed recess with a forwardly faced wall or shoulder therein, a replaceable gun barrel insertable into this recess to a position to engage this wall or shoulder and a simple means for holding the barrel in the recess during use of the gun.

A further object of the invention is to provide a novel ignition unit for use in perforating guns.

Further objects and advantages of the invention will be brought out in the following part of the specification, wherein specific details of construction are for the purpose of fully disclosing specinc embodiments of the invention without limiting the scope thereof set forth in the appended claims.

Referring to the drawings which are for illustrative purposes only,

Fig. 1 is a partly sectioned elevational view of a portion of a perforating gun embodying my invention.

Fig. 2 is a cross section taken as indicated by the line 2 2 of Fig. 1.

Fig. 3 is a cross sectional view of a gun barrel wherein an alternative construction is shown.

Fig. 4 is a cross sectional View similar in general to Fig, 2, but showing a diiferent gun barrel assembly.

Fig. 5 is a sectional view taken as indicated by the line 5 5 of Fig. 4.

In Fig. 1 I show a portion of a gun body I0 which consists of a cylindric bar of a size to be lowered into a well casing. Since the manner of supporting or suspending perforating gun bodies by means of cables or tubing strings is well known, I have merely shown that portion of a gun body embracing my invention. The gun body IIJ has therein a plurality of laterally directed recesses II which preferably consist of cylindric bores formed on diametral lines and facing in different directions. Each of the recesses I I has therein a forwardly faced wall or shoulder I2 to serve as stops against which the inner ends of inserted gun barrel assemblies I3 may rest. The recesses II have openings I4 at the rear ends thereof, through which force may be applied to the rear ends of the barrel assemblies I3 when it is desired to force them from the recesses II.

As shown in Figs. 1 and 2, the gun barrel assemblies i3 are of cylindric form and fit relatively snugly in the recesses II. Simple means in the form of screws I5 are provided for firmly securing the gun barrel assemblies I3 in the recesses II. These screws I5 are operative in threaded openings IS, each of which communicates with a side of afrecess II so that the inner ends of the screws I5 may engage the side walls or surfaces of the gun barrel assembliesV I3, as shown. As best shown in Fig. 2, each gun barrel assembly I3 comprises a main barrelniember I1 and a cooperating member I8.

The main barrel member I'I has therein an axial bore I9 to receive a projectile 20, and at the inner end of the bore I9 there is a chamber 2I to receive a powder charge 22. In the form of the invention shown in Fig. 2, the chamber 2| constitutes an enlargement at the inner end of the bore I9 formed-by drilling an opening laterally in from a side of the member II. At` the outer end of the chamber 2i there is a counterbore 23 having at its inner end a shoulder 24 against which the cooperating member I8 rests. The powder chamber 2| is dened by the mem- Acharge chamber 3|. `sotl'iat the explosion ofthe ignition charge 32a bers II and I8, and when these members i1 and I8 are moved apart, for example, by moving the cooperating member I3 laterally and outwardly with relation to the axis of the bore I9, when the barrel assembly I3 is removed from the recess II, the chamber 2I will be open or accessible so that the powder charge 22 may be placed therein. In cooperation with the wall or closure I8 I provide a sealing member 25Vcomprising a plug which is pressed into the counterbore 23. When the member I8 and the plug 25 are in place, the wall V25 of the recess I I p-revents removal of the member I8, or, in other words, prevents separation or disassembly of the cooperating parts I1 and I8 of the barrel assembly I3.

n'the 'outer end of each gun bore I9 there is a combined bore sealing and ignitionrunit 26. This unit 2E comprises a cylindric body 21 having a iiange 28 at its outer end to engage the front end face of the member I'I `when the unit 2SY is pressed into `the bore I9 thereof. Adjacent the iiange 28, Vthe body 2l' has an annular channel 29 to receive a rubber sealing ring 3G which makes sealing engagement with the wall ofthe bore I9. At the inner end of the ybody 25 there is `an inwardly faced 'cavity Si in which an ignition charge 32 of powder is placed, Vafter which the cavity is closed by an end wall or disc member '-3'3. An electrical fuse vor filament wire S eX- tends Vwithin the chamber or cavity 3l, and the ends of this wire 34 are carried outwardly through the member 2'( to the exterior where they are connected to vconductors 35 which lie in a spiralV projectiles 2K@ outwardly through the bores I9 at high velocity.

In the formof the invention shown in Figs. i and 2, the pressure of fluids encountered in the well are kept from forcing the projectiles 2) inwardly by the sealing and ignition units .25 vhaving .flanges 28 so that they cannot be forced vinwardly .from the positions in which they are 'installed in the gun bores I9. In Fig. 3 I show va gun 'barrel assembly i3d which is mostly comprised or the same parts as the barrel assembly I3 shown in Fig. 2. Therefore, these corresponde Y ging or identical parts will Vbe identied by the .numerals previously used so as to avoid repetition of description. In Fig. 3 I show a sealing and ignition unit 26awhich is inserted in the bore I and has its end -wall 33 recessed so that it will Vfit-'over lthe nose of the projectile 20. This unit 26d differs from the .unit A26 shown in Fig. 2 in Van additional respect-namely, that it does not employ a flange 28, but has a rubber sealing plug 3fm 4at its outer end for sealing the bore I9 against entry of fluid. At the inner end of the fprojectile'Eil there is means 38 for preventing Y inward movement of the projectile 2li from ,the`

position in which the projectile is shown by the 4hydraulic pressure of the well exerted against Y `the sealing plug Bea.. The means 38 is shown as a perforated metal disc disposed in the firing It may be made 'frangi-ble will cause it to be crushed by the inwardly driven projectileZU, or this means .38 may ,be of such strength that it will prevent inward movement of the projectile 2G under the force of the explosion of the ignition charge 32a. In this latter event, the firing charge 22, Fig. 3, will be ignited by the flame and products of combustion from the explosion of the ignition charge 32a whichV pass through the rearward portion ofthe bore I9, across the outer face ofthe projectile 2i) into the powder chamber 3l, it being understood that a small space existing between the surface of the projectile and the wall of the bore I9, forms a passage for the combustion products.

In Figs. 4 and 5 I show a gun body I ila. having Va recess `I Ia of cy-lindric lform -with a shoulder 12a near its frontend instead cf near the rear end of the recess as shown Vin Figs. -1 and 2. `A gun barrel assembly 4I) is provided having :at its `front end flange means II for engagement with the shoulderrlIZa. This barrel assembly MI has a bore 42 to `receive a projectile 63, anda powder chamber le is provided at the rear Aend of =`the bore `i752 to receive a firing rcharge 45.

The vbarrel assembly ill of Fig. 4 comprises separable parts for accomplishing Yaccess y-to the powder'chamber fifi when the assembly 40 is removed from Ythe recess lia. These separable Yparts include a pair of symmetrical, semi-V-cylindrical body members S so as to provide an outer shell El for the assembly d which is divided along a median plane .43. Y

Leading inwardly from its front end, the shell il has an axial open-ing 56 to receive a steel tubeh -l inV which the bore 22 is formed and which has at its rearY end a rearwardly faced cavity 52 which cooperates with a wplug or closure -53 in forming .the powder chamber et.

In the is a sealing vand ignition unit `55 which combines the characteristics of the units 25 and 26a shown in Figs. 2 and 3; 'That is to say, this unit 55 Vhas an Vexternal ange 28 which rests lagainst the outer end `ofrthe tubular member 5I, has a sealingring 3B" adjacent the flange 2B" and rhas at its inner end a recess wall 33a which fits over hthe Anose of the projectile t3. The unit 55 carries van ignition charge .32h arranged to 4be eX- plcded by the heating of a lament 35a so as to produce a force which will drive the projectile i3 rearwardly to cause 'the ring of the powder charge 45.

I claim as my invention? In a well periorating gun, the combination oi: .barrel recess; a gun barrel assembly insertable into said recess, said gun barrel assembly comprising a main ybarrel member having a bore for receiving a projectile, a powder receiving space Aat the Ainner end of said fbore, said space having an opening leading ,out through the side of 'said Amain lbarrel member, and a wall member -toclose lsaid opening, saidwall member being arranged Y ward movement of said projectile;V and Ameans' in the outer end `of said bore to produce Van explosion which will drive said projectile finto usaid powder receiving fspace.

2. Ina well `perforating gun, the combination of a gun body hav-ing Vaflaterally Adirected gun bar-rel recess; -a gun Abarrel assembly insertable The closureV '53 is provided with a lsealing ring 54.

.outer end of the projectile receiving bore Vt2 there a gun vbody having a laterally directed *gunY into said recess, said gun barrel assembly comprising a main barrel member having a bore for receiving a projectile, a powder receiving space at the inner end of said bore, said space having an opening leading out through the side of said main barrel member, and a wall member to close said opening, said wall member being arranged so that it will be held in place by the side wall of said recess when said barrel assembly is in said recess; means for resisting inward movement of said projectile; and means in the outer end of said bore to produce an ignition effect in the outer part of said bore which will pass by the projectile and ignite the powder charge in said powder receiving space.

3. In a well perforating gun, the combination of: a gun body having a bore for receiving a projectile, and a powder receiving space at the inner end of said bore; a projectile in said bore; a charge of powder in said space; yieldable means distinguished from said powder disposed in said powder receiving space so as to engage and resist inward movement of said projectile and thereby prevent compression of powder in said chamber as the result of inadvertent inward movement of said projectile; and means in the outer end of said bore to produce an explosion which will drive said projectile into said powder receiving space.

4. In a well perforating gun, the combination of 1 a gun body having a bore for receiving a projectile, and a powder receiving space at the inner end of said bore, said space having a rear wall; a. projectile in said bore; a charge of powder in said space; means distinguished from said powder" REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,212,045 Ridley Aug. 20, 1940 2,250,056 Alexander July 22, 1941 2,307,729 Foster Jan. 5, 1943 2,351,179 Aloi June 13, 1944 w2,402,153 Elliott June 18, 1946 2,419,841 Lampel Apr. 29, 1947 2,433,231 Martin Dec. 23, 1947 

